Mortality Remains High for STEMI Patients Complicated by Cardiogenic Shock

The significant reduction of in-hospital mortality related to ST-segment elevation acute myocardial infarction (STEMI) has been greatly attributed to the overwhelming adoption of primary percutaneous intervention (PCI). STEMI patients with cardiogenic shock (CS) tend to experience a higher mortality even after PCI and the implantation of mechanical circulatory support (MCS) devices.

A recent retrospective study published in European Heart Journal: Acute Cardiovascular Care assessed the mortality benefit, if any, of reperfusion via primary PCI for patients with STEMI complicated with CS of 466 patients enrolled in the Coronary Revascularization Demonstrating Outcome Study in Kyoto (CREDO-Kyoto) acute myocardial infarction (AMI) registry.

For the purpose of this study, CS was defined by the following Killip class IV criteria:

• Systolic blood pressure < 90 mmHg
• Vasoconstriction manifestations
  • Cyanosis
  • Diaphoresis
  • Oliguria

To evaluate the primary outcome measure of all-cause mortality for these patients, researchers looked at the cumulative incidence of all-cause death in the patients with STEMI complicated by CS due to acute pump failure. The recorded incidence was as follows:

• 25.4% at 30 days
• 38.7% at 12 months
• 51.4% at five years

Researchers found that a shorter onset-to-balloon (OTB) time (< 3 hours) resulted in a significantly lower rate of death (Figure 1) compared to prolonged OTB (43.3% and 55.5%, respectively). There were similar findings between short and long door-to-balloon (DTB) time (44.9% vs 55.8%, respectively). Additionally, early reperfusion was associated with a lower rate of mortality.

While the patient population used in this study was relatively small (n=3942), the data shows mortality rates continue to remain high among patients with STEMI complicated with CS caused by acute pump failure. Implementing shorter OTB and DTB times, at least according to this study, may result in improved long-term survival.

Reference:

1. Kawaji T, Shiomi H, Morimoto T, et al. Long-term clinical outcomes in patients with ST-segment elevation acute myocardial infarction complicated by cardiogenic shock due to acute pump failure. Eur Heart J Acute Cardiovasc Care. 2016.

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